There was little between the teams for almost two-thirds of the contest, but Gustavo Hamer's 57rh-minute strike opened the all-too familiar floodgates.
Two quickfire strikes followed from Viktor Gyokeres and the Sky Blues had netted three times in seven minutes to end the game as a contest and condemn Posh to their fifth straight away defeat in the Sky Bet Championship.
And to compound a miserable evening, Siriki Dembele suffered what looked a serious injury in stoppage time.
Thankfully, he was helped to walk off the field rather than on the stretcher that was ominously carried on the field, but it still didn't look good.
The win took Coventry top of the table, while Posh, who have still never won at what is now called the Coventry Building Society Arena, remain fourth from bottom.
The surprise team news was that striker Jonson-Clarke Harris was allowed to play, with Posh having appealed the four-match ban he had been handed by the Football Association for offensive historic tweets.
That move allowed Darren Ferguson to name an unchanged team from the one that beat Birmingham City on Saturday.
Posh had to repel a strong start from the home side in a cracking atmosphere.
Gradually they got a foothold in the game, and started to pass the ball about, but it was the home side who created the first real chance.
Viktor Gyokeres skinned Ronnie Edwards in the left channel and pulled the ball back to Callum O'Hare, but he scuffed his shot from eight yards.
Then followed a spell of cat and mouse as both sides probed for openings without success, the organised Posh defence snuffing out any Sky Blues attacks before they hit the danger area.
With half-an-hour gone, neither keeper had made a save.
Dembele did offer a shooting chance to Gustavo Hamer as his loose pass gifted the ball to the Coventry man 25 yards out, but his powerful drive flew inches over rhe top, before O'Hare air-kicked at a ball that flashed across the six-yard box.
If he'd connected, it would have been a goal.
Coventry had a big appeal for a penalty on 38 minutes, but referee Geoff Eltringham deemed Joe Ward's challenge on Ian Maatsen to be a fair one. There was no ball involved, and It was debatable.
Seconds before the break the Sky Blues won a free-kick on the edge of the box that was sent a whisker over the top by Hamer with Dai Cornell beaten, before Martyn Waghorn blazed a good opening miles over the bar to leave it 0-0 at the break.
Ferguson made a change at the interval, handing Kwame Poku his Posh League debut with Joe Ward making way.
The first opening of the second half fell to the Sky Blues, and Gyokeres, but he screwed the ball tamely wide of the left hand post after turning Dan Butler inside out to create the chance.
The Swede went even closer minutes later, but his goalbound effort after a corner was headed into his path six yards out was cleared off the line by Clarke-Harris with Cornell beaten.
The home side were sensing blood, and on 57 minutes they got their reward - and it came from a lightning break from a rare Posh corner.
Coventry cleared their lines and swept up the other end, with the ball landing at the feet of Hamer on the right edge of the six yard box.
His first effort was brilliantly blocked on the line by Jack Taylor, but the rebound was kind and he thumped the ball home at the second attempt.
The CBS Arena was jumping now, and the volume went another notch or 10 just minutes later as the home side doubled their lead, Hamer this time the creator.
The Dutch playmaker got clear down the right and his pinpoint cross was bundled home by Gyokeres from close range - he couldn't miss.
Posh were now all over the place, and almost unbelievably they conceded a third on 64 minutes, Gyokeres taking advantage of some weak defending in the area by Butler, with his shot then deflecting off Frankie Kent and into the net.
Three goals in seven minutes, and the game was over.
Posh did at least regain some composure and shape, but it was far too little too late.
The home side certainly seemed happy with what they had as the game petered out to the backdrop of the jubilant home supporters in the 20,000 crowd celebrating going top of the pile.
As the game entered stoppage time, Posh did at least get their first shot on target, but Sky Blues goalkeeper Simon Moore saved well from Harrison Burrows who had broken clear through the middle.
Then, with seconds remaining, Dembele went down after hurting himself chasing back and challenging for the ball.
This was a night when there was nothing for Posh to cheer.
Coventry: Simon Moore, Ian Maatsen (87m, Jodi Jones), Jake Clarke-Salter, Kyle McFadzean, Dominic Hyam, Todd Kane, Jamie Allen, Gustavo Hamer (80m Liam Kelly), Callum O’Hare, Martyn Waghorn, Viktor Gyokeres (80m, Tyler Walker) Subs not used: Ben Wilson, Michael Rose, Ben Sheaf, Matty Godden
Posh: Dai Cornell, Dan Butler, Frankie Kent, Ronnie Edwards, Nathan Thompson, Oliver Norburn, Jack Taylor (65m, Conor Coventry), Siriki Dembele, Jorge Grant (73m, Harrison Burrows), Joe Ward (46m, Kwame Poku), Jonson Clarke-Harris. Subs not used: Will Blackmore, Sammie Szmodics, Josh Knight, Joe Tomlinson
Referee: Geoff Eltringham
Goals: Hamer, 57m - 1-0; Gyokeres, 61m - 2-0; Gyokeres 64m - 3-0;
Booking: Butler (44m);